Received error messages extracting by attributes

Question

Hi everyone,

I have a raster dataset (NLCD2006 Land Cover raster from http://www.mrlc.gov/nlcd06_data.php) that I am working with. I tried to extract the portion of it using the "extract by attributes" in the spatial analyst. I received an error message using this method. My goal is to have a raster that only includes the Values :21,22,23,24,25,81,and 82. There are 290 rows in the raster dataset and I only need 7 rows.

Class                                         Value
Developed-Open Space                 21
Developed-Low Intensity         22
Developed-Medium Intensity         23
Developed-High Intensity         24
Pasture/Hay                         81
Cultivated Crops                         82

So I tried another way, I selected the rows and created a dataset in ASCII format, hoping to convert the ASCII to raster. I received error messages using that method as well.

My very end goal is to represent the % land use values on a county level. Once I can create the raster dataset I need, I want to use zonal statistics as table (using the raster and my study region shapefile) to calculate the % land use values for each county.

I would appreciate it if you can point to what I may be doing wrong or direct me to a better way of creating the raster dataset I need. I also attached some screenshots as well.

Thanks for your help in advance.

RasterProblems.docx

Teresa_Blader_0-1780417252647.png

curtvprice · Answer

My very end goal is to represent the % land use values on a county level.

It's important to only work with the data that you need. Set the geoprocessing extent to just cover your study area, and try the Tabulate Area tool to tabulate up your areas by county (easiest using a code like FIPS, not by name).

One more thing, you may have better luck using the SQL operator "IN" with that tool:

VALUE IN (21,22,23,24)

MalcolmNunn · Answer

Those errors suggest that some general troubleshooting might be helpful. Try:

- turn off background processing in Geoprocessing -> Geoprocessing Options, or
- move the input and output data to a different, publically accessible location.

Cheers
Malcolm

GrljAles · Answer

Try doung it the other way arount using Set Null to all values that you do not need.